1. Field of the Invention
The present invention relates to waste treatment systems and especially those waste treatment which are packaged or containerized units. Even more particularly, the present invention relates to an aerated waste treatment apparatus in which air flow provides hydraulic drive of the treatment apparatus and combines with preferably a pair of baffles to move waste to be treated in a helical path within a cylindrical vessel.
2. General Background and Prior Art
In the treatment of waste, there is often utilized a containerized or packaged sewage treatment plant which treats a received waste product on a continuous basis.
In the marine industry for example, there is utilized a packaged sewage treatment plant which can be used on ships, oil rigs, and like installations. Such sewage treatment devices usually receive flow intermittently and must threat the flow in order to meet ecological and other marine standards.
It is desirable that waste be treated such as sewage in an economical way utilizing as little energy as possible and as few moving parts as possible.
It would also be desirable that a minimum of sludge removal would be required since the sludge disposal presents an extra problem.
It would further be appreciated that the settling of sludge on any parts of the apparatus would present a sludge removal problem. Further, the accumulation of sludge within the unit would produce an undesirable possibly corrosive attack on the unit itself. An accumulation of sludge within the unit further results in a deterioration of the treatment process.
It would be desirable that a sludge treatment apparatus produce a total homoginization of the fluids received from the waste stream in order that they be probably bio-degraded. Waste entering the unit would normally be heterogeneous in nature, containing solid waste material as well as some liquid material. A breakup of this material is necessary in order that it be treated properly.
In aerated treatment systems, a problem is faced in that a clogging of the aeration assembly which provides bubbles to the unit will cause a degeneration of the treatment process or in fact a total stoppage of air flow to the vessel, transferring the process from aerobic to an anaerobic thus removing any treatment capability. It would be desirable that the aeration unit or air diffuser be of a nature which would reduce or prevent clogging by solid material which enters the unit.
A further problem seen in waste treatment devices of this type is that of chlorination. Chlorination normally must be provided to the unit as needed and not on a continuous basis. If chlorine is constantly provided to the unit it will be appreciated that over chlorination and waste of chlorine will be seen when low flow occurs. Conversely, high flow periods would provide an under chlorination and the ineffective killing of microorganisms before waste water is discharged from the unit. It would be desirable that a balanced system be provided for chlorinating any effluent material based on the actual volume of fluid which was to be chlorinated within the given time.
3. General Discussion of the Present Invention
The present invention solves these prior art problems and shortcomings by providing a waste treatment apparatus having no moving parts in the basic hydraulic system.
The waste treatment apparatus of the present invention provides a cylindrical vessel adapted to receive waste water flow therethrough to be treated. The vessel provides an aeration chamber at the outer periphery portion thereof with a desirable generally helical flow being generated by aeration bubbles striking angularly deposed baffle plates which are statically mounted within the aeration chamber. A clarifier is mounted at the central portion of the cylindrical vessel for clarifying a liquid which enters the clarifier from the aeration chamber through the clarifier inlet. The clarifier comprises a first settling chamber and a second decant chamber through which clear water is collected and transmitted to a chlorination chamber for subsequent discharge. The angularly deposed static baffle plates are mounted in the upper portion of the aeration chamber and aid in spinning the waste water in a circular or curved path. Likewise, a pair of aeration diffusers mounted in the lower portion of the aeration chamber near the center of the cylindrical vessel move waste water to be treated upwardly and outwardly in a circular path. The combination of the diffusers and the baffles moves the waste water in a generally helical path for prolonged contact time and improved mechanical masceration. Additionally, the helical path thus generated tends to move solids in a centrifugal fashion away from the clarifier entrance further enhancing the separation of solids from the decant liquor.
Thus, it is an object of the present invention to provide a waste treatment apparatus in which apparatus parts are provided at an angle which disallows the settling of sludge and related solids on the apparatus.
It is another object of the present invention to provide a waste treatment apparatus providing a helical flow pattern of the waste treatment stream.
Another object of the present invention is to provide a waste treatment apparatus having a constant scrubbing action which prevents sludge accumulation and the resulting deterioration of the treatment process.
Still another object of the present invention is to provide a waste treatment apparatus having a centrifugal motion of fluids within the treatment vessel combined with a central clarifier, the centrifugal force tending to move solids and other undesirable suspended material away from the clarifier reducing opportunity to enter the clarifier thereby improving the mechanical separation of the solid/liquid waste stream.
It is another object of the present invention to provide an air diffuser which produces a bubble stream having a high surface area.
It is another object of the present invention to provide an aeration diffuser adapted to disallow the accumulation of sludge or other undesirable deposits within the diffuser assembly, and to disallow the clogging of bubble generating orifices by waste solid material.
Still another object of the present invention is to provide a waste treatment apparatus which eliminates the need for sludge removal and further sludge treatment.
Another object of the present invention is to provide a chlorination chamber which chlorinates waste stream based on the volume of waste stream effluent.
Still another object of the present invention is to provide a chlorine contact chamber which confines effluent and chlorine for concentrated chlorine contact prior to allowing a mixing of the chlorine and most recent effluent with the dilute effluent prior to a discharge from the unit.
Still another object of the present invention is to provide a waste treatment system which is gravity operated, utilizing no other energy dependent driving force.
Another object of the present invention is to provide a waste treatment system which can be retrofitted to existing installations, especially those having cylindrical tank portions.
It is a further object of the present invention to provide a waste treatment apparatus having distinct liquid operating levels which are maintained without the use of pumps or valves.